Paper used in the application for food, such as wrapping paper, containers, and cooking paper, is provided with water repellency, oil repellency to prevent oily or aqueous ingredients of the food from penetrating into the paper and staining its surroundings. Paper is also provided with non-tackiness to prevent the food from sticking to the paper and from being deformed or broken when the food is taken out.
To provide water and oil repellency and non-tackiness, treating agents have been used, which comprise various kinds of compounds having a perfluoroalkyl group such as polymers having a perfluoroalkyl group. Most of these treating agents have been widely used in a form of an aqueous dispersion in an internal addition method or an external addition method in paper making processes.